Prime Minister Justin Trudeau says Canada needs to be vigilant about protecting the integrity of its electoral systems from foreign interference.

He offered that assessment in a Toronto press conference in response to questions about the influence of Russian President Vladimir Putin, who was re-elected this week to six more years in power.

In some of his sharpest criticism yet of the Russian leader, Trudeau says Putin needs to start playing a more positive role in the world on a variety of fronts — from Ukraine, to Syria as well as answering for Russia’s role in the nerve gas attack in Britain two weeks ago.

Trudeau said Wednesday the heavy use of social media and interference by foreign actors are the new reality in elections.

Trudeau’s remarks come after several recent warnings about possible Russian interference in Canada’s 2019 federal election, including from eastern European diplomats in Ottawa, as well as a top NATO researcher.

Trudeau reiterated how he has tasked Democratic Institutions Minister Karina Gould with shoring up Canada’s electoral system against foreign meddling.

“We have been very much focused over the past years on strengthening our democratic institutions,” he said, “… to recognize the new environment in which we will now be holding democratic elections, which often involves heavy use of social media, possible foreign interference.

“We need to make sure that they are kept up to date in holding off foreign meddling and interference.”

Relations between Canada and Russia are strained with the Canadian Forces commanding a NATO battle group in Latvia — part of the alliance’s anti-Moscow deterrent in Eastern Europe following the Kremlin’s annexation of Ukraine’s Crimean Peninsula in 2014, and the ongoing turmoil in eastern Ukraine.

Russia has threatened unspecified retaliation against Canada for its passage of anti-corruption legislation. It has also placed Foreign Affairs Minister Chrystia Freeland on a list of people banned from travelling to the country because of her past writing about Putin during her former career as a journalist.

Trudeau said Putin needs to change his behaviour.

“President Putin needs to start showing by his actions that he wants to play a positive role in the international community,” the prime minister said during a Toronto press conference.

“Whether it’s pulling back of his engagement in the Donbass or leaving Crimea, whether it’s taking responsibility for the questions — the important questions that the U.K. has asked after the terrible poisoning incident a few weeks ago in Salisbury, whether it’s questions around NATO, questions around Syria, questions around the Arctic.”

The House of Commons unanimously adopted a motion this week that blames Russia for what it calls a despicable nerve gas attack in Britain.

Freeland put forward the motion, saying Russia has shown a total disregard for the rules of the international order.

Former double agent Sergei Skripal and his daughter Yulia were found unconscious on a bench in the city of Salisbury two weeks ago. The British government says they were the victims of a Russian nerve agent.